
This cake mix toffee bar recipe simplifies homemade dessert with store-bought cake mix while delivering irresistible layers of buttery toffee, rich chocolate, and gooey sweetened condensed milk. My kitchen testers always ask for seconds when I make these crowd-pleasing bars.
I first made these for my daughter's school bake sale and came home with an empty container and several requests for the recipe. Now they're our go-to dessert whenever we need something sweet without spending hours in the kitchen.
Ingredients
- Yellow cake mix: creates the perfect cookie dough texture without measuring multiple dry ingredients
- Unsalted butter: adds richness while allowing you to control the salt level
- Large eggs: bind everything together and provide structure
- Toffee bits: deliver delightful crunch and caramel flavor throughout
- Sweetened condensed milk: creates gooey pockets of sweet creamy goodness
- Chocolate chips: melt slightly during baking for pockets of chocolate bliss
Step-by-Step Instructions
- Preheat the Oven:
- Set your oven to 350°F (175°C) and lightly grease your 9×13-inch baking pan. The light coating of grease ensures easy removal without the bars sticking to the pan.
- Create the Perfect Batter:
- In a large bowl, combine the cake mix, melted butter, and eggs until fully incorporated. The dough will be thick and slightly sticky, similar to cookie dough. Make sure no dry spots remain for the best texture.
- Form the Bottom Layer:
- Press exactly half of your batter into an even layer in the prepared pan. Take your time with this step, using slightly damp fingers if needed to prevent sticking, ensuring coverage across the entire bottom of the pan.
- Layer the Fillings:
- Evenly distribute the chocolate chips and toffee bits over your base layer, creating a generous filling. Then slowly drizzle the sweetened condensed milk in a zigzag pattern for even coverage, being careful not to pour it all in one spot.
- Create the Top Layer:
- Drop remaining dough by spoonfuls over the filling, then gently press and connect the pieces, leaving some gaps where filling peeks through. This creates attractive marble-like appearance and allows the filling to caramelize.
- Bake to Golden Perfection:
- Bake for exactly 25 minutes, then check for doneness. The edges should be golden brown and slightly pulling away from the pan, while the center remains slightly soft but set. Add 2-3 more minutes if needed.

My family particularly loves the toffee bits in this recipe. My husband claims they remind him of his grandmother's famous butter cookies that always had that distinct buttery toffee flavor around the edges where the sugar caramelized.
Make Ahead and Storage
These toffee bars maintain their freshness beautifully when stored properly. Keep them in an airtight container with parchment paper between layers to prevent sticking. They'll stay delicious at room temperature for 4 days. For longer storage, wrap individual bars in plastic wrap then place in a freezer bag for up to 3 months. Let thaw at room temperature for about an hour before serving.
Easy Substitutions
The versatility of this recipe makes it perfect for customizing. Swap the yellow cake mix for chocolate cake mix and use white chocolate chips for a reverse version. Replace toffee bits with chopped heath bars, butterscotch chips, or even crushed pretzels for a sweet-salty combo. For a nutty variation, add 1/2 cup chopped pecans or walnuts to the filling layer. During holiday season, mix in 1/4 cup festive sprinkles for colorful celebration bars.

Serving Suggestions
While these bars are perfect on their own, elevating them creates memorable dessert experiences. Warm each bar for 10 seconds in the microwave and top with premium vanilla ice cream for an indulgent dessert. Drizzle with warm caramel sauce and a sprinkle of sea salt for sophisticated presentation. Cut into smaller squares and arrange on a platter with fresh berries for elegant entertaining. For special occasions, dust with powdered sugar and serve alongside coffee or hot chocolate.
Frequently Asked Questions
- → Can I use a different type of cake mix?
Yes! While yellow cake mix is recommended for its flavor, white or chocolate cake mix can also be used for a variation in taste.
- → How do I store these bars?
Store the bars in an airtight container at room temperature for up to 4 days. You can also freeze them individually for up to 3 months.
- → Can I use other toppings or fillings?
Absolutely! Try adding nuts, caramel chips, or even peanut butter chips for a creative twist.
- → Do I need to refrigerate the bars?
No, the bars keep well at room temperature. However, refrigeration can extend their freshness slightly if needed.
- → How do I know when the bars are done baking?
The edges should be golden and set, while the center remains slightly gooey. Let the bars cool completely before slicing.